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Ecosystems / WEFE Nexus

Publication // An impact analysis of population growth on energy‐water‐food‐land nexus for ecological sustainable development in Rwanda

By Imasiku, K. and Ntagwirumugara, E. (2019). This research article analyzes the ecological balance of human activities in Rwanda and how policymakers have increasingly emphasized on energy–water–food nexus sectors separately without integrating land usage and population growth, which might pose an even more critical situation if left unattended to.


To date, many studies have been conducted in Rwanda concerning energy–water–food nexus issue which has all pointed to land as being a critical factor in the energy–water– food nexus sectors. In 2017, Josefine Axelsson and Emelie Johnson of KTH Royal Institute of Technology presented in their research, on the Food–Water–Energy nexus assessment in Rwanda highlighting that the Climate, Land, Energy, and Water (CLEW) technique that integrates different models can investigate land, energy, and water use developments while considering climate change impacts. The CLEW is a framework for integrated assessment of resource systems and modeling using quantitative tools like LEAP1 (Long‐range Energy Alternatives Planning System) or OSeMOSYS2 (Open Source Energy Modeling System) for energy, WEAP3 (Water Evaluation and Planning System) for water use while the AEZ4 (Agro‐Ecological Zones) is for land use.

Though thorough work is being done on the Energy–water–food nexus sectors, these sectors will according to empirical evidence have the climate change affect the water availability but not dramatically (Josefine & Emelie, 2017). Further studies on the Rwanda Energy–ater–ood sectors by Oliver W. Johnson et al. of Stockholm Environment Institute in Sweden explored the water–energy–nood nexus in Rwanda's Akagara Basin in 2018. Both studies showed that while hydropower in Rwanda will continue to play a significant role in the electricity mix until 2050, it depends on water availability and rain patterns (Johnson et al., 2018). The expected water scarcity demands a thorough water management system in Rwanda. These previous studies show that the outcome of their studies is not conclusive because of several land assumptions made on the soil types and that the land usage exclusion warrants the need for more inclusive studies. The following are some expected challenges by 2050 if Rwanda takes no measures (Johnson et al., 2018);

  • Over‐exploiting land through human activities reduces the ability for water to run off and this causes floods.
  • Unplanned human settlement causes landslides. In 2018, Landslides in Rwanda killed at least 18 people in May 2018, bringing the death toll to 200 by the end of 2018 (Rwanda landslides after heavy rain brings 2018 death toll to 200, BBC News, 2018).
  • At a growth rate of 2.95%, the population will increase to 32.1 million by 2050 while the total land area will remain 26,338 km2 (Why Rwanda's population is increasing so fast). This scenario will increase the water, food, and energy consumption in Rwanda and consequently lead to the pressure on land, biomass resources, and water ecosystems because of the high population, adversely changing the climate.
  • A further reduction of the land size is expected because a segment of the future energy production is expected to be generated from peat. Rwanda plans to utilize approximately 100,000 ha of wetlands reserves and harvest the carbonized vegetable matter in Rwabusoro, Akanyaru, Murago, Gihitasi, Mashya, Gishoma, Rucahabi, Cyato, Cyabararika, Nyirabirande, Kageyo, Kaguhu, Mashoza, Gasaka, Bahimba, Bisika, Rwuya, Nyabigongo, and Rugeramigozi (Rwanda Energy Sector Review and Action Plan, African Development Bank Group, 2013). This activity also poses a major threat to wetland ecosystems.

However, planning water, food, and energy projects without considering land usage in Rwanda will lead to land stress because water, food, energy, and land sectors are interdependent. The conclusions made from the electricity, food, and water model calculations in previous studies are that all these sectors have multiple and complex social, economic, and environmental effects on Rwanda. Land usage and scarcity was considered as a possible extension of their studies. (Johnson et al., 2018; Josefine & Emelie, 2017; Strategic Plan for the Transformation of Agriculture in Rwanda –Phase II (PSTA II), 2009).

It is with this background that our study aims at investigating the effects of disconnected approaches of dealing with energy–ood–ater nexus projects in isolation with land usage and plans an integrated approach to these issues. The study illustrates the basic methods and suggests practical tools which the Rwandan Government can utilize, through its implementing agencies to account for the energy–water–ood–and nexus sectors in an integrated manner that provides a clear nexus status for sound decision making. The proposed approach offers a multiscale and integrated assessment methodology that presents a comprehensive accounting approach of resource management sustainably to achieve ecological sustainable development (ESD) in Rwanda. Ecological sustainable development is necessary to improve the quality of lives for many Rwandans today and in future while maintaining an ecological balance of all‐natural and socioeconomic activities of man without regard to the cost implications attached to environmental well‐being (Ecological Sustainable Development, Aron Brown Gas Project EIS, Aron Energy, 42626960/G/Rev A, 2012).

Key messages

In Rwanda and many other countries, food production affects water by causing changes in the way land is used as well as monitoring any changes in the river runoffs and groundwater discharge levels. Modern agriculture practices (SMART or Precision) that depend on fertilization for crop nutrition may cause groundwater pollution with nitrates, be energy‐intensive and infrastructure intensive and yet less‐labor intensiveif adopted as a mitigation or adaptation technique. Further, the food and agriculture supply chain networks may use up more than the average 30% global consumption because its economy is 90% agricultural dependent. All these factors need careful analysis in the context of the food–ater–nergy–land–opulation growth nexus. This food–water–energy–and–population growth nexus issue presents a complex scenario in Rwanda which requires careful analysis to resolve by 2050 when the pressure is expected to be more severe if left unattended to.

For instance, it is not easy to deal with a population density of 1,219 people per km2. At a growth rate of 2.95%, the population of Rwanda will increase from about 13.03 million in 2019 to 32.1 million people by 2050. This demographic ramp will cause an increase in water, energy, and food consumption and this will pose more pressure on the land resource. The consumption increase projections in this research paper are based on population growth and only presents the consumption by human beings and do not include industrial or agricultural activities and waste. Therefore, some critical questions worth noting are as follows: Is Rwanda planning for the projected population growth, industrial usage or any waste, the new industries, and cities with their demands? The authors conclude that It would be worth it for Rwanda to develop plans that will critically analyze the resources and formulate strategies of how to control the demographics (birthrate), while ensuring that that effective water and landuse models, efficient energy production systems or any other human activities are monitored, planned and coordinated in a manner that will not compromise on the community andthe environment. This would enhance ecological sustainable development in Rwanda.


August 2019


© 2019 The Authors.


Imasiku, K., & Ntagwirumugara, E. (2020). An impact analysis of population growth on energy‐water‐food‐land nexus for ecological sustainable development in Rwanda.

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